The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 13, 1997
Filed:
Dec. 27, 1994
Maximilian H Hobelsberger, CH-5303 Wurenlingen, CH;
Other;
Abstract
Loudspeaker system with closed housing for improved bass reproduction. The loudspeaker system operates utilizing pressure control in the closed loudspeaker housing. This pressure control suppresses pressure changes of the air inside the housing. The control circuit comprises a pressure sensor, a controller, a power amplifier and an electrodynamic transducer inside the housing. The membrane of the transducer is covered with piezoelectric material and conducting coatings forming piezoelectric sensors to measure the changes of the air pressure upon the surface. The piezoelectric material consists of polyvinylidene fluoride, PVDF. The sensors are specially shaped to avoid distortions. They differ in thickness for the elimination of acceleration-dependent signal terms.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile